Infection of rhesus macaques with simian immunodeficiency virus (SIV) or simian-human immunodeficiency virus (SHIV) is a key animal model for HIV-1 infection. The Nonhuman Primate (NHP) Scientific Research Support Component (SRSC) aims to support this CHAVI-ID by providing all the expertise, infrastructure, reagents, personnel, and animals for the conduct of complex in vivo immunogenicity and challenge studies in NHPs. This SRSC will involve leadership from both Beth Israel Deaconess Medical Center and the Yerkes National Primate Research Center (Emory University) and is well positioned to meet the CHAVI-ID goals. This SRSC leadership will work closely with the research discovery teams responsible for the studies described in Scientific Foci #1 and#2 and participate actively in the scientific mission of this CHAVI-ID. The main role of this SRSC is to provide leadership and technical expertise to ensure consistency and quality control in animal selection, execution of study protocols, experimental procedures, sample acquisition and distribution, immunologic and virologic studies, and data collection and analysis. The Specific Aims are: 1. To support this CHAVI-ID by selecting and providing rhesus macaques, providing exceptional animal care, conducting experimental studies with monoclonal antibodies (MAbs) and vaccines, collecting samples for immunologic and virologic testing, and performing necropsy studies. These studies will initially evaluate: A. Protective efficacy of HIV-1 Env-specific MAbs against SHIV challenge; B. Immunogenicity and protective efficacy of novel HIV-1 Env immunogens and immunization strategies; 2. To support this CHAVI-ID by providing blood and tissue samples from SIV/SHIV-infected and uninfected NHPs to collaborating investigators to underpin basic research studies. These samples will support studies of neutralizing Abs in Focus #1 and will help elucidate the characteristics of virus-specific CD4+ follicular helper T cell (Tfh) responses in Focus #2, with an initial emphasis on the development of Tfh cells during vaccine-induced immune responses and the role of Tfh cells in promoting the affinity maturation of antibodies.